FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/evc_parse.h
Date: 2024-04-20 14:10:07
Exec Total Coverage
Lines: 5 7 71.4%
Functions: 1 1 100.0%
Branches: 1 2 50.0%

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1 /*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19 /**
20 * @file
21 * EVC decoder/parser shared code
22 */
23
24 #ifndef AVCODEC_EVC_PARSE_H
25 #define AVCODEC_EVC_PARSE_H
26
27 #include <stdint.h>
28
29 #include "libavutil/intreadwrite.h"
30 #include "libavutil/log.h"
31 #include "evc.h"
32 #include "evc_ps.h"
33
34 // The sturcture reflects Slice Header RBSP(raw byte sequence payload) layout
35 // @see ISO_IEC_23094-1 section 7.3.2.6
36 //
37 // The following descriptors specify the parsing process of each element
38 // u(n) - unsigned integer using n bits
39 // ue(v) - unsigned integer 0-th order Exp_Golomb-coded syntax element with the left bit first
40 // u(n) - unsigned integer using n bits.
41 // When n is "v" in the syntax table, the number of bits varies in a manner dependent on the value of other syntax elements.
42 typedef struct EVCParserSliceHeader {
43 uint8_t slice_pic_parameter_set_id; // ue(v)
44 uint8_t single_tile_in_slice_flag; // u(1)
45 uint8_t first_tile_id; // u(v)
46 uint8_t arbitrary_slice_flag; // u(1)
47 uint8_t last_tile_id; // u(v)
48 uint32_t num_remaining_tiles_in_slice_minus1; // ue(v)
49 uint16_t delta_tile_id_minus1[EVC_MAX_TILE_ROWS * EVC_MAX_TILE_COLUMNS]; // ue(v)
50
51 uint8_t slice_type; // ue(v)
52 uint8_t no_output_of_prior_pics_flag; // u(1)
53 uint8_t mmvd_group_enable_flag; // u(1)
54 uint8_t slice_alf_enabled_flag; // u(1)
55
56 uint8_t slice_alf_luma_aps_id; // u(5)
57 uint8_t slice_alf_map_flag; // u(1)
58 uint8_t slice_alf_chroma_idc; // u(2)
59 uint8_t slice_alf_chroma_aps_id; // u(5)
60 uint8_t slice_alf_chroma_map_flag; // u(1)
61 uint8_t slice_alf_chroma2_aps_id; // u(5)
62 uint8_t slice_alf_chroma2_map_flag; // u(1)
63 uint16_t slice_pic_order_cnt_lsb; // u(v)
64
65 // @note
66 // Currently the structure does not reflect the entire Slice Header RBSP layout.
67 // It contains only the fields that are necessary to read from the NAL unit all the values
68 // necessary for the correct initialization of the AVCodecContext structure.
69
70 // @note
71 // If necessary, add the missing fields to the structure to reflect
72 // the contents of the entire NAL unit of the SPS type
73
74 } EVCParserSliceHeader;
75
76 // picture order count of the current picture
77 typedef struct EVCParserPoc {
78 int PicOrderCntVal; // current picture order count value
79 int prevPicOrderCntVal; // the picture order count of the previous Tid0 picture
80 int DocOffset; // the decoding order count of the previous picture
81 } EVCParserPoc;
82
83 606 static inline uint32_t evc_read_nal_unit_length(const uint8_t *bits, int bits_size, void *logctx)
84 {
85 606 uint32_t nalu_len = 0;
86
87
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606 if (bits_size < EVC_NALU_LENGTH_PREFIX_SIZE) {
88 av_log(logctx, AV_LOG_ERROR, "Can't read NAL unit length\n");
89 return 0;
90 }
91
92 606 nalu_len = AV_RB32(bits);
93
94 606 return nalu_len;
95 }
96
97 int ff_evc_parse_slice_header(GetBitContext *gb, EVCParserSliceHeader *sh,
98 const EVCParamSets *ps, enum EVCNALUnitType nalu_type);
99
100 // POC (picture order count of the current picture) derivation
101 // @see ISO/IEC 23094-1:2020(E) 8.3.1 Decoding process for picture order count
102 int ff_evc_derive_poc(const EVCParamSets *ps, const EVCParserSliceHeader *sh,
103 EVCParserPoc *poc, enum EVCNALUnitType nalu_type, int tid);
104
105 #endif /* AVCODEC_EVC_PARSE_H */
106